proto fw: add helper trait for cursor

src/libboard_artiq/src/cxp_proto.rs

@@ -65,22 +65,44 @@ fn get_cxp_crc(bytes: &[u8]) -> u32 {
     (!checksum_ieee(bytes)).swap_bytes()
 }
 
+trait CxpRead {
+    fn read_4x_u8(&mut self) -> Result<u8, Error>;
+
+    fn read_u32(&mut self) -> Result<u32, Error>;
+}
+impl<Cursor: Read> CxpRead for Cursor {
+    #[inline]
+    fn read_4x_u8(&mut self) -> Result<u8, Error> {
+        // TODO: add error correction
+        let mut bytes = [0; 4];
+        self.read_exact(&mut bytes)?;
+        Ok(bytes[0])
+    }
+
+    #[inline]
+    fn read_u32(&mut self) -> Result<u32, Error> {
+        let mut bytes = [0; 4];
+        self.read_exact(&mut bytes)?;
+        Ok(u32::from_be_bytes(bytes))
+    }
+}
+
 fn capture_ctrl_packet(reader: &mut Cursor<&mut [u8]>, with_tag: bool) -> Result<DownConnPacket, Error> {
     let mut tag: Option<u8> = None;
     if with_tag {
-        tag = Some((read_word(reader)? & 0xFF) as u8);
+        tag = Some(reader.read_4x_u8()?);
     }
 
-    let ackcode: u8 = (read_word(reader)? & 0xFF) as u8;
+    let ackcode = reader.read_4x_u8()?;
 
     match ackcode {
         0x00 => {
-            let length = read_word(reader)?;
+            let length = reader.read_u32()?;
             let mut data: [u8; DATA_MAXSIZE] = [0; DATA_MAXSIZE];
             reader.read(&mut data[0..length as usize])?;
 
             let checksum = get_cxp_crc(&reader.get_ref()[0..reader.position()]);
-            let recv_checksum = read_word(reader)?;
+            let recv_checksum = reader.read_u32()?;
             println!("calculated checksum = {:#010X}", checksum);
             println!("read checksum = {:#010X}", recv_checksum);
             if recv_checksum != checksum {
@@ -90,12 +112,12 @@ fn capture_ctrl_packet(reader: &mut Cursor<&mut [u8]>, with_tag: bool) -> Result
         }
         0x01 => return Ok(DownConnPacket::CtrlAck { tag }),
         0x04 => {
-            let length = read_word(reader)?;
+            let length = reader.read_u32()?;
             let mut time: [u8; DATA_MAXSIZE] = [0; DATA_MAXSIZE];
             reader.read(&mut time[0..length as usize])?;
 
             let checksum = get_cxp_crc(&reader.get_ref()[0..reader.position()]);
-            let recv_checksum = read_word(reader)?;
+            let recv_checksum = reader.read_u32()?;
             println!("calculated checksum = {:#010X}", checksum);
             println!("read checksum = {:#010X}", recv_checksum);
             if recv_checksum != checksum {
@@ -107,6 +129,22 @@ fn capture_ctrl_packet(reader: &mut Cursor<&mut [u8]>, with_tag: bool) -> Result
     }
 }
 
+pub fn receive(channel: usize) -> Result<(), Error> {
+    unsafe {
+        let ptr = CXP_RX_MEM[channel].base as *mut u32;
+        let mut reader = Cursor::new(slice::from_raw_parts_mut(ptr as *mut u8, MEM_LEN));
+        let packet_type = (CXP[channel].downconn_packet_type_read)();
+
+        let packet = match packet_type {
+            0x03 => capture_ctrl_packet(&mut reader, false),
+            0x06 => capture_ctrl_packet(&mut reader, true),
+            _ => return Err(Error::UnknownPacket(packet_type)),
+        };
+        println!("{:?}", packet);
+    }
+    Ok(())
+}
+
 #[derive(Debug)]
 pub enum UpConnPacket {
     CtrlRead {
@@ -133,12 +171,6 @@ pub enum UpConnPacket {
     },
 }
 
-fn read_word(reader: &mut Cursor<&mut [u8]>) -> Result<u32, Error> {
-    let mut bytes = [0; 4];
-    reader.read(&mut bytes)?;
-    Ok(u32::from_be_bytes(bytes))
-}
-
 impl UpConnPacket {
     pub fn write_to(&self, writer: &mut Cursor<&mut [u8]>) -> Result<(), Error> {
         // CoaXpress use big endian
@@ -199,7 +231,8 @@ impl UpConnPacket {
                     writer.write(&data[0..length as usize])?;
                 }
 
-                writer.write(&get_cxp_crc(&writer.get_ref()[4..writer.position()]).to_be_bytes())?;
+                let checksum = get_cxp_crc(&writer.get_ref()[4..writer.position()]);
+                writer.write(&checksum.to_be_bytes())?;
             }
             _ => {}
         }
@@ -207,22 +240,6 @@ impl UpConnPacket {
     }
 }
 
-pub fn receive(channel: usize) -> Result<(), Error> {
-    unsafe {
-        let ptr = CXP_RX_MEM[channel].base as *mut u32;
-        let mut reader = Cursor::new(slice::from_raw_parts_mut(ptr as *mut u8, MEM_LEN));
-        let packet_type = (CXP[channel].downconn_packet_type_read)();
-
-        let packet = match packet_type {
-            0x03 => capture_ctrl_packet(&mut reader, false),
-            0x06 => capture_ctrl_packet(&mut reader, true),
-            _ => return Err(Error::UnknownPacket(packet_type)),
-        };
-        println!("{:?}", packet);
-    }
-    Ok(())
-}
-
 pub fn send(channel: usize, packet: &UpConnPacket) -> Result<(), Error> {
     if unsafe { (CXP[channel].upconn_tx_enable_read)() } == 0 {
         Err(Error::LinkDown)?
@@ -268,50 +285,50 @@ fn send_test_packet(channel: usize) -> Result<(), Error> {
 //
 //
 //
-pub fn write_u32(channel: usize, addr: u32, data: u32) -> Result<(), Error> {
-    let mut data_slice: [u8; DATA_MAXSIZE] = [0; DATA_MAXSIZE];
-    data_slice[..4].clone_from_slice(&data.to_be_bytes());
-    send(
-        channel,
-        &UpConnPacket::CtrlWrite {
-            tag: None,
-            addr,
-            length: 4,
-            data: data_slice,
-        },
-    )?;
+// pub fn write_u32(channel: usize, addr: u32, data: u32) -> Result<(), Error> {
+//     let mut data_slice: [u8; DATA_MAXSIZE] = [0; DATA_MAXSIZE];
+//     data_slice[..4].clone_from_slice(&data.to_be_bytes());
+//     send(
+//         channel,
+//         &UpConnPacket::CtrlWrite {
+//             tag: None,
+//             addr,
+//             length: 4,
+//             data: data_slice,
+//         },
+//     )?;
 
-    Ok(())
-}
+//     Ok(())
+// }
 
-pub fn read_u32(channel: usize, addr: u32) -> Result<(), Error> {
-    send(
-        channel,
-        &UpConnPacket::CtrlRead {
-            tag: None,
-            addr,
-            length: 4,
-        },
-    )?;
+// pub fn read_u32(channel: usize, addr: u32) -> Result<(), Error> {
+//     send(
+//         channel,
+//         &UpConnPacket::CtrlRead {
+//             tag: None,
+//             addr,
+//             length: 4,
+//         },
+//     )?;
 
-    Ok(())
-}
+//     Ok(())
+// }
 
-pub fn write_u64(channel: usize, addr: u32, data: u64) -> Result<(), Error> {
-    let mut data_slice: [u8; DATA_MAXSIZE] = [0; DATA_MAXSIZE];
-    data_slice[..8].clone_from_slice(&data.to_be_bytes());
-    send(
-        channel,
-        &UpConnPacket::CtrlWrite {
-            tag: None,
-            addr,
-            length: 8,
-            data: data_slice,
-        },
-    )?;
+// pub fn write_u64(channel: usize, addr: u32, data: u64) -> Result<(), Error> {
+//     let mut data_slice: [u8; DATA_MAXSIZE] = [0; DATA_MAXSIZE];
+//     data_slice[..8].clone_from_slice(&data.to_be_bytes());
+//     send(
+//         channel,
+//         &UpConnPacket::CtrlWrite {
+//             tag: None,
+//             addr,
+//             length: 8,
+//             data: data_slice,
+//         },
+//     )?;
 
-    Ok(())
-}
+//     Ok(())
+// }
 
 pub fn print_packet(pak: &[u8]) {
     println!("pak = [");